Storage system including a plurality of battery modules

ABSTRACT

In a storage system provided with a plurality of storage modules, the rated power consumption can be reduced. The storage system is provided with a charge control unit. The charge control unit Stops, when detecting that a predetermined number of a plurality of battery modules are during battery charging, the battery charging in the remaining battery modules.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.12/232,157 filed Sep. 11, 2008. Priority is claimed from U.S.application Ser. No. 12/232,157 filed Sep. 11, 2008, which claimspriority from Japanese Patent Application No. 2008-190188, filed on Jul.23, 2008, the entire disclosure of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a storage system including a pluralityof battery modules.

2. Description of the Related Art

A storage system including a plurality of battery modules has been wellknown. The battery modules are each generally provided with a battery,and a charger that makes a supply of direct current from a power sourceto the battery. When a power failure or any power source failure occurs,with power provided by the battery modules, data stored in a volatilememory, e.g., cache memory, is backed up on nonvolatile storageresources, e.g., hard disk or flash memory.

Patent Document 1 (JP-A-9-215217) describes a battery charging devicethat can charge a plurality of batteries. Patent Document 2(JP-A-10-271705) describes a power source circuit provided with acharging circuit that supplies a charging current to a battery in abattery pack. Patent Document 3 (JP-A-2002-78227) describes a batterycharging control device that controls both an electronic device and apower supply to a battery in accordance with a priority over operationor battery charging.

A storage system desirably has the lower rated power consumption. As animprovement therefor, charging control over the storage system, i.e., aplurality of batteries in a plurality of battery modules, is worthy ofnote.

The concern here is that none of above Patent Documents 1 to 3 describesa technology applicable to charging control over such a storage system,i.e., the batteries in the battery modules. That is, Patent Documents 1merely describes one battery module, i.e., battery charging device, andPatent Document 2 merely describes one battery module, i.e., batterypack. Patent Document 3 merely describes one battery.

SUMMARY OF THE INVENTION

An object of the invention is to reduce the rated power consumption of astorage system including a plurality of storage modules.

A storage system is provided with a charge control unit. The chargecontrol unit stops, when detecting that a predetermined number of aplurality of battery modules are during battery charging, the batterycharging in the remaining battery modules.

As an exemplary configuration, a plurality of battery modules are eachprovided with a charger that supplies power from a power source to thebattery of its own, and a charge controller that controls a power supplyfrom the charger to the battery. In this configuration, a plurality ofcharge controllers respectively provided in the battery modulesconfigure a charge control unit. The charge controllers are eachconnected to one or more of the remaining charge controllers by one ormore first signal lines and one or more second signal lines. On thefirst signal line(s), a signal indicating the state of charge in thebattery module including the charge controller flows, and on the secondsignal line(s), a signal indicating the state of charge in the one ormore of the remaining battery modules including the one or more of theremaining charge controllers. The charge controllers each determinewhether there is an indication of during-charging for the signalsflowing over a predetermined number of the one or more second signallines. When such a determination result is negative, the chargecontrollers each put the charger in its own battery module in charge tomake the power supply therefrom to the battery, and when thedetermination result is positive, the charge controllers each make thecharger to stop the power supply therefrom to the battery.

The number of the battery modules may be even or odd. To be specific,for example, a storage system may be provided with one or more pairs ofthe battery modules, or with a plurality of battery modules not paired.With the former case, in each of the pairs, when one of the batterymodules is during battery charging, the remaining battery module is notduring battery charging.

The storage system is provided with a plurality of controllers, forexample. When a predetermined number or more of the controllers are inthe state of low power consumption, the predetermined number or more ofthe battery modules may be allowed to be charged all at once.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an external perspective view of a storage system of a firstembodiment of the invention, viewed from the front;

FIG. 1B is another external perspective view of the storage systemthereof, viewed from the rear;

FIG. 2A is a front view of a backboard;

FIG. 2B is a rear view of the backboard;

FIG. 3 is a diagram showing the internal configuration of the storagesystem of the first embodiment of the invention;

FIG. 4 is a diagram showing the internal configuration of a batterymodule of the first embodiment of the invention;

FIG. 5 is a flowchart of a charge control process;

FIG. 6 is a diagram showing the internal configuration of a storagesystem in a first modified example of the first embodiment of theinvention;

FIG. 7 is a diagram showing a battery module in a second modifiedexample of the first embodiment of the invention;

FIG. 8 is a diagram showing the internal configuration of a storagesystem of a second embodiment of the invention; and

FIG. 9 shows a process to be executed by a controller in the secondembodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the below, several embodiments of the invention are described.

First Embodiment

FIG. 1A is an external perspective view of a storage system of a firstembodiment of the invention, viewed from the front. FIG. 1B is anexternal perspective view of the storage system, viewed from the rear.Herein, various components configuring the storage system are notrestricted in number as below, e.g., controllers, battery modules, andAC/DC (Alternating Current/Direct Current) power supplies.

In a chassis 1, a backboard 210 (refer to FIGS. 2A and 2B) is providedeach on the front and rear surface sides for partitioning the space inthe chassis 1.

As shown in FIG. 2A, the backboard 210 on the front side is providedwith a plurality of HDD-use connectors 203 for connection with aplurality of hard disk drives (HDDs) 10, and two battery-module-useconnectors 201A and 201B for connection with two battery modules 11.Accordingly, as shown in FIG. 1A, the chassis 1 is incorporated with, onthe front surface side, a plurality of HDDs 10 and the two batterymodules 11. As alternatives to the HDDs 10, any other types of physicalstorage devices, e.g., flash memory devices, may be provided.

As shown in FIG. 2B, the backboard 210 on the rear surface side isprovided with two cooling-module-use connectors 215A and 215B forconnection with two cooling modules 12, two power-supply-use connectors211A and 211B for connection with two AC/DC power supplies 13, and twocontroller-use connectors 213A and 213B for connection with twocontrollers 14. Accordingly, as shown in FIG. 1B, the chassis 1 isincorporated with, on the rear surface side, the two cooling modules 12,the two AC/DC power supplies 13, and the two controllers 14.

The two battery modules 11 are respectively inserted into twobattery-module-use slots 18. These slots 18 are each assigned a number.As will be described later, the numbers (slot numbers) assigned to theslots 18 can be each acknowledged by the inserted battery module 11receiving a signal of the slot number from the connectedbattery-module-use connector 201A (or 201B).

The two cooling modules 12 are disposed on the right and left on theupper stage on the rear surface side. The cooling modules 12 are eachprovided with three fans 121. In the chassis 1, by these fans 121, theHDDs 10 and the controllers 14 are cooled.

The AC/DC power supplies 13 each convert an alternating current from acommercial power supply into a direct current, and supply the resultingcurrent to various types of loads. These two AC/DC power supplies 13 aredisposed side by side on the lower stage on the rear surface side. TheAC/DC power supplies 13 are each provided with two fans 131. The fans131 cool the AC/DC power supplies 13 and the battery modules 11.

The HDDs 10 are disposed side by side on the upper stage on the frontsurface side. The two battery modules 11 are disposed side by side onthe lower stage on the front surface side.

The two controllers 14 are disposed one on the other on the upper stageon the rear surface side, i.e., the controller 14 on the upper side isdisposed upside down with respect to the controller 14 on the lowerside. The controllers 14 are each in charge of control over datatransfer with any host device such as host computer, and control overdata transfer with the HDDs 10. The controllers 14 each monitor thestate of the components, i.e., the cooling modules 12, the AC/DC powersupplies 13, and the remaining controllers 14, and control the fans 121of the cooling modules 12 and the fans 131 of the AC/DC power supplies13.

FIG. 3 shows the internal configuration of the storage system. Notethat, in FIG. 3, the reference numerals of any redundant components,i.e., the AC/DC power supplies, the controllers, and the batterymodules, are configured by parent numbers of 13, 14, and 11 with childnumbers of A and B. The two cooling modules 12 and the backboards 210are not shown in FIG. 3.

From the two AC/DC power supplies 13A and 13B, a direct current isprovided via the backboards 210 to the components, i.e., a plurality ofHDDs 10, the two battery modules 11A and 11B, the two controllers 14Aand 14B, and the two cooling modules 12. The two controllers 14A and 14Bare respectively provided with volatile memories 141A and 141B. Thevolatile memories 141A and 141B are each a cache memory, for example.These cache memories temporarily store data received by the controllers14A and 14B from the host device of a storage system 100, e.g., hostcomputer, for writing into the HDDs 10, and data read by the controllers14A and 14B from the HDDs 10 for transmission to the host device.

Even if either the AC/DC power supply 13A or 13B stops its operation dueto failure or others, if the remaining AC/DC power supply 13B or 13A canmake a power supply, the loads can be operated. That is, the storagesystem 100 can be operated in its entirety. If this is the case, forexample, the volatile memories 141A and 141B are provided with no powersupply from the batteries in both the battery modules 11A and 11B.However, when a detection is made in the storage system 100 that thepower supply both from the AC/DC power supplies 13A and 13B is cut off,the batteries in the two battery modules 11A and 11B discharge all atonce so that the loads, i.e., at least the volatile memories 141A and141B, are provided with the power supply from the batteries in the twobattery modules 11A and 11B. The power from the batteries is consumed bya data backup process. To be specific, while there is a power supplyfrom the batteries to the volatile memories 141A and 141B, the backupprocess is executed to save the data stored in the volatile memories,e.g., especially data not yet written into the HDDs 10, to the HDDs 10.The HDDs 10 are not restrictive, and may be nonvolatile storageresources of any other type.

The battery modules 11A and 11B are connected to each other by twosignal lines 301A and 301B. These two signal lines 301A and 301B areprinted on the backboards 210, for example. Signals flowing over thesignal lines 301A and 301B are those indicating the state of charge.Such signals are hereinafter referred to as charge-state signals. To bespecific, signals flowing over the signal line 301A are those indicatingthe state of charge in the battery module 11A, and signals flowing overthe signal line 301B are those indicating the state of charge in thebattery module 11B. The charge state signals are voltage-level signals,for example.

In the below, the internal configuration of the battery modules 11A and11B is described with an example of the battery module 11A.

FIG. 4 is a diagram showing the internal configuration of the batterymodule 11A. The remaining battery module 11B has the same internalconfiguration of FIG. 4.

The battery module 11A is configured to include a battery 503, a switch507, a charger 505, and a charge control microcomputer 501.

The switch 507 is in charge of switching betweenpower-supply/no-power-supply from the battery 503 to the volatilememories 141A and 141B in the controllers 14A and 14B. The switch 507 isgenerally being turned ON. Herein, even if the switch 507 is beingturned ON, while there is a power supply from the AC/DC power supply 13Aand/or 13B to the volatile memories 141A and 141B, the power from thebattery 503 is not reaching the volatile memories 141A and 141B, andwhen the power supply from both the AC/DC power supplies 13A and 13B isstopped to the volatile memories 141A and 141B, the power from thebattery 503 reaches the volatile memories 141A and 141B.

The charger 505 can be in the ON/OFF state and when being in the ONstate, the charger 505 supplies the direct-current power from the AC/DCpower supplies 13A and 13B to the battery 503, and when being in the OFFstate, the charger 505 does not make such a supply to the battery 503.

Through control over the ON/OFF state of the charger 505 as such, thecharge control microcomputer 501 controls the power supply/no-powersupply from the charger 505 to the battery 503.

The signal lines 301A and 301B are connected to the charge controlmicrocomputer 501. While battery charging is performed in the batterymodule 11A, the charge control microcomputer 501 changes, to H level,the level of a charge-state signal flowing over the signal line 301A. Inaccordance with the level of a charge-state signal flowing over thesignal line 301B, the charge control microcomputer 501 controls theON/OFF state of the charger 505.

A connector 509 provided in the battery module 11A is connected to thebattery-module-use connector 201A or 201B provided to the backboard 210.Through the connector 201A or 201B being connected as such, the chargecontrol microcomputer 501 is provided with a signal indicating a slotnumber assigned to the slot 18 inserted with the battery module 11A.

The charge control microcomputer 501 monitors a signal 507 representingthe voltage of the battery 503. When detecting that the voltage of thebattery 503 is reduced to a first threshold value or smaller due tonatural discharge, for example, the charge control microcomputer 501starts a charge control process of FIG. 5. The charge control process ofFIG. 5 is started not only when the voltage of the battery 503 isreduced to a first value or smaller as such but also when the storagesystem 100 is activated for the first time, i.e., when power is turnedon for the storage system 100 that has been provided with no power fromthe AC/DC power supplies 13A and 13B, and when a discharge occurs fromthe battery 503 due to power failure or others.

Although not shown, the battery module 11A is provided with an outputsection that indicates the state in the battery module 11A. The outputsection is configured by one or more LEDs (Light-Emitting Diodes), e.g.,green and red LEDs. These LEDs are controllably turned ON or OFF by thecharge control microcomputer 501. To be specific, the green LED isturned ON when the battery 503 stores enough power for backup for apredetermined duration of time, i.e., when the battery 503 has thevoltage of a second threshold value or larger, and blinks during batterycharging, e.g., as a result of the battery 503 not having enough power,or as a result of the storage system 100 being activated for the firsttime. During supplemental battery charging, i.e., when the battery 503has some level of power, the green LED is not blinked but is turned ON.When the battery module 11A becomes incapable of data backup or othersdue to a failure or others, the green LED is turned OFF but the red LEDis turned ON. By the red LED being turned ON as such, an operator isencouraged to exchange the battery module 11A.

FIG. 5 is a flowchart of a charge control process to be executed by thecharge control microcomputer 501 in the battery module 11A.

When a charging command comes, the charge control process isresponsively started. The charging command is issued, as describedabove, when the battery 503 has the voltage of the first threshold valueor smaller, when the storage system 100 is activated for the first time,and after a discharge from the battery 503 due to power failure orothers.

The charge control microcomputer 501 determines whether any other systemis during battery charging or not (S601). To be specific, the chargecontrol microcomputer 501 determines whether a charge-state signalflowing over the signal line 301B is at the H level or not.

When the determination result of 5601 is positive (S601: YES), thecharge control microcomputer 501 does not perform the battery charging,i.e., does not turn ON the charger 505. After the lapse of a fixedlength of time, e.g., after the lapse of five minutes, (S602), thecharge control microcomputer 501 executes the process of S601.

When the determination result of 5601 is negative (S601: NO), the chargecontrol microcomputer 501 turns ON the charge-state signal flowing overthe signal line 301A (changes the signal level from L to H) (S603).After the lapse of a fixed length of time, e.g., after the lapse of fiveseconds (S604), the charge control microcomputer 501 determines whetherany other system is during battery charging or not (S605). That is, thecharge control microcomputer 501 determines whether the remaining module11B is during the battery charging or not.

When the determination result of 5604 is negative (S605: NO), the chargecontrol microcomputer 501 turns ON the charger 505 so that the batterycharging is started (S606). When detecting that the battery 503 is fullycharged from the signal 507 representing the voltage of the battery 503,for example (S607: YES), the charge control microcomputer 501 stops thebattery charging by turning OFF the charger 505, and turns OFF thecharge-state signal flowing over the signal line 301A, i.e., changes thesignal level from H to L (S608).

When the determination result of 5605 is positive (S604: YES), thecharge control microcomputer 501 determines whether the slot number is“0” or not (S609). As an example, when the battery module 11A isconnected to the battery-module-use connector 201A, a signalrepresenting the slot number “0” is provided to the charge controlmicrocomputer 501.

When the determination result of 5609 is positive (S609: YES), thecharge control microcomputer 501 executes the process of 5606, i.e., thebattery charging is started. Note that, in this case, because the slotnumber “0” is not detected in the remaining module 11B, the batterycharging is not started therein, i.e., the charge-state signal flowingover the signal line 301B is turned OFF.

On the other hand, when the determination result of 5609 is negative(S609: NO), the charge control microcomputer 501 turns OFF thecharge-state signal flowing over the signal line 301A (S610). That is,the battery charging is not started. After the lapse of a predeterminedlength of time (S611), the charge control microcomputer 501 executes theprocess of 5601.

As such, in the first embodiment, the charge control microcomputer 501of one of the battery modules, i.e., the battery module 11A, is soconfigured as to be able to detect the charge state in the remainingbattery module 11B. When detecting that the battery charging is inprogress in the battery module 11B, the charge control microcomputer 501does not perform the battery charging even if a charging command isprovided. This thus favorably prevents the battery charging from beingperformed at the same time in the two battery modules 11A and 11B in thestorage system 100, thereby being able to suppress the rated powerconsumption in the storage system 100.

In the embodiment above, when the charge-state signal is at the H levelboth in the signal lines 301A and 301B at the same time, thesimultaneous battery charging is prevented from being performed in thetwo battery modules 11A and 11B in the process of 5609 of FIG. 5.Alternatively, the requirements for use to determine which of the twomodules 11A and 11B is firstly battery-charged are not restrictive tothe slot number “0”, and any other type of requirements will also do.

Moreover, in the above first embodiment, the number of the backupmodules is two. Alternatively, the number of the backup modules may bedetermined in accordance with the storage capacity of the volatilememories 141A and 141B. This is because the amount of data to be savedinto the HDDs 10 by the backup process is varied in accordance with thestorage capacity of the volatile memories.

To be specific, as a first modified example, for example, as shown inFIG. 6, two battery module pairs may be provided. If this is the case,every battery module pair is connected with a signal line (301A, 301B)and (301C, 301D) for connecting the battery modules (11A, 11B) and (11C,11D) configuring the battery module pair.

The battery modules are not necessarily in pair. In other words, thenumber of the battery modules may be odd. If this is the case, thebattery modules can each detect the charge state of any other batterymodules. Specifically, as a second modified example, when four batterymodules are provided in the storage system 100, as shown in FIG. 7, thecharge control microcomputers 501 in the respective battery modules areconnected to three signal lines (301A, 301B) leading to the chargecontrol microcomputers in the three other battery modules. The chargecontrol microcomputer 501 changes, when the battery charging is inprogress in the battery module of its own, the level of the charge-statesignals flowing over the three signal lines 301A all at once to H, andwhen the battery charging is not in progress in the battery module, thecharge-state signals flowing over the three signal lines 301A arechanged in level to L all at once. The charge control microcomputer 501can also detect how many other battery modules are during the batterycharging depending on how many of the three signal lines 301B arecarrying the charge-state signal of H level. When detecting that anyother k battery modules are during the battery charging (where k is aninteger of 1 or larger), the charge control microcomputer 501 is allowednot to start the battery charging in the battery module of its own.

Second Embodiment

In the below, a second embodiment of the invention is described. Herein,only any difference from the first embodiment is mainly described, andthe remaining is not described or simply described.

FIG. 8 is a diagram showing the internal configuration of a storagesystem of the second embodiment of the invention.

The controllers 14A and 14B are respectively connected with the firstand second signal lines 301A and 301B. The controller 14A or 14B detectsthe state of the remaining controller 14B or 14A. The state of thecontrollers includes a state of first power consumption, e.g., operatingstate, and a state of second power consumption, e.g., standby state. Inthe state of second power consumption, the power consumption is lower inlevel than the state of first power consumption.

When the controller 14A in the state of first power consumption detectsthat the remaining controller 14B is in the state of second powerconsumption (S901 of FIG. 9: YES), the charge-state signals flowing overthe first and second signal lines 301A and 301B are cancelled (S902 ofFIG. 9). The expression of “the charge-state signals are cancelled”means that the charge-state signals are not received by the chargecontrol microcomputer. Accordingly, when the controller 14B is in thestate of second power consumption, the battery charging can be performedat the same time in the two battery modules 11A and 11B.

In this embodiment, exemplified below are (Power A) and (Power B).(Power A) denotes the power consumption as a result of battery chargingin one battery module, and (Power B) denotes a difference of powerconsumption in one controller between the state of first powerconsumption and the state of second power consumption.

(Power B) is larger than (Power A), and thus when the controller is inthe state of second power consumption, the battery charging may beperformed at the same time in the two batter modules 11A and 11B.

This second embodiment can be applied to various other modified examplesof the first embodiment.

In a first modified example, for example, the first and second signallines (301A, 301B) and (301C, 301D) of each of the battery module pairsare connected with the controllers 14A and 14B, respectively. When thecontroller 14B is in the state of low power consumption, at least forone battery module pair, the controller 14A in the normal state cancelsthe charge-state signal flowing over the first and second signal lines(301A, 301B) and/or (301C, 301D).

About the cancellation of the charge-state signals in how many batterymodule pairs, it is set in advance or dynamically based on any desiredrated power consumption for the storage system and (Power A) and (PowerB) described above.

Ina second modified example, for example, every pair of signal lines(301A, 301B) is connected with the controllers 14A and 14B. In thiscase, when the controller 14A in the operating state detects that theremaining controller 14B is in the state of low power consumption, thecharge-state signal flowing at least over a pair of first and secondsignal lines (301A, 301B) is cancelled. About the cancellation of thecharge-state signals flowing over how many battery module pairs, it isset in advance or dynamically based on any desired rated powerconsumption for the storage system and (Power A) and (Power B) describedabove.

-   -   While the embodiments and the modified examples of the invention        have been described in detail, the foregoing description is in        all aspects illustrative and not restrictive. It is understood        that numerous other modifications and variations can be devised        without departing from the scope of the invention. For example,        as an alternative to the method of notifying, i.e., detecting,        the charge state by a voltage-level signal, the charge state may        be notified, i.e., detected, by wireless communications by        infrared radiation or others.

1. A storage system, comprising: a power source; a plurality of batterymodules each having a battery configured to be charged with powersupplied by the power source; a plurality of controller components thatcontrol access to a plurality of physical storage devices, eachcontroller component being provided with a volatile memory that receivesa power supply from the power source if any, and if: not, receives apower supply front the battery of at least any one of the plurality ofbattery modules; and a charge control unit that, upon receiving acharging command for any of the battery modules, detects a quantity ofthe battery modules that are undergoing charging, and wherein the chargecontrol unit initiates charging of the battery in any battery module forwhich a charging command is received upon detecting that the quantity ofthe battery modules that are undergoing charging is less than apredetermined number of the battery modules, and the charge controlunit, upon detecting that the predetermined number of the plurality ofbattery modules are undergoing battery charging, stops charging of thebattery in any remaining of the battery modules.
 2. The storage systemaccording to claim 1, wherein the battery modules are each provided witha charger that supplies the power supply from the power source to thebattery of the battery module and a charge controller that controls apower supply from the charger to the battery of the battery module, thecharge control unit is configured by the plurality of charge controllersrespectively provided to the plurality of battery modules, the chargecontrollers are each connected to one or more of the other chargecontrollers by one or more first signal lines over which a signal flowsfrom the charge controller to the one or more of the other chargecontrollers to which the charge controller is connected, the chargecontrollers are each connected to one or more second signal lines overwhich a signal flows to the charge controller from the one or more ofthe other charge controllers to which the charge controller isconnected, and in each of the battery modules, the charge controllerprovided to the battery module is configured to, upon the battery of thebattery module having a voltage of a first value or smaller, perform thefollowing operations: (2-1) determine whether there is an indication ofthe predetermined number of battery modules undergoing charging from thesignals flowing over the one or more second signal lines to which thecharge controller is connected, (2-2) regard, upon determining thatthere is not an indication of the predetermined number of the batterymodules undergoing charging in operation (2-1), the signals flowing overthe one or more first signal lines as signals indicating that thebattery module to which the charge controller is provided is undergoingcharging, (2-3) determine, upon completing operation (2-2), whetherthere is an indication of the predetermined number of battery modulesundergoing charging from the signals flowing over the one or more secondsignal lines to which the charge controller is connected, (2-4) put,upon determining that there is not an indication of the predeterminednumber of the battery modules undergoing charging in operation (2-3),initiates the power supply from the charger provided to the batterymodule to which the charge controller is provided to the battery of thebattery module, and upon the voltage of the battery of the batterymodule to which the charge controller is provided being increased to atleast a second value that is equal to or larger than the first value,stop the power supply from the charger to the battery, and regard thesignals flowing over the one or more first signal lines as signalsindicating that the battery module to which the charge controller isprovided is not undergoing charging.
 3. The storage system according toclaim 2, further comprising: a circuit board including apower-source-use connector for connection with the power source, aplurality of battery-module-use connectors for connection with theplurality of battery modules, and a plurality of controller-useconnectors for connection with the plurality controller components,wherein each of the charge controllers is configured to perform thefollowing operations: (3-1) determine, upon determining that there is anindication of the predetermined number of the battery modules undergoingcharging in operation (2-3), whether the battery module to which thecharge controller is provided is connected to a predetermined one of anyof the plurality of battery-module-use connectors, (3-2) put, upondetermining that the battery module to which the charge controller isprovided is connected to the predetermined battery-module-use connectorin operation (3-1), initiates the power supply from the charger providedto the battery module to which the charge controller is provided to thebattery of the battery module, and upon the voltage of the battery ofthe battery module to which the charge controller is provided beingincreased to at least the second value, stop the power supply from thecharger to the battery, and regard the signals flowing over the one ormore first signal lines as signals indicating that the battery module towhich the charge controller is provided is not undergoing charging, and(3-3) regard, upon determining that the battery module to which thecharge controller is provided is not connected to the predeterminedbattery-module-use connector in operation (3-1), the signals flowingover the one or more first signal lines as signals indicating that thebattery module to which the charge controller is provided is notundergoing charging, and after a lapse of a predetermined length oftime, execute operation (2-1).
 4. The storage system according to claim3, wherein the plurality of battery modules are configured in one ormore battery module pairs, and for each of the charge controllers, anyof the other charge controllers provided to a battery module that is ina battery module pair with the battery module to which the chargecontroller is provided is an other-end charge controller to the chargecontroller, and the charge controller and the other-end chargecontroller are connected by any of the one or more first signal linesover which a signal flows from the charge controller to the other-endcharge controller and connected by any of the one or more second signallines over which a signal flows from the other-end charge controller tothe charge controller.
 5. The storage system according to claim 4,wherein in each of the battery module pairs, the battery modules areconnected by any of the one or more first signal lines and any of theone or more second signal lines, the plurality of controller componentsare respectively connected with the one or more first signal lines andthe one or more second signal lines based on based on connectionsbetween the battery module pairs, and upon a predetermined number of theplurality of controller components being in a state of second powerconsumption that is lower in power consumption than a state of firstpower consumption, and upon any of the plurality of controllercomponents that are in the state of first power consumption making adetection of the predetermined number of the plurality of controllercomponents being in a state of second power consumption, the detectingcontroller components cancel the signal flowing over any of the firstand second signal lines between each of the battery modules.
 6. Thestorage system according to claim 1, wherein the battery modules areeach provided with a charger that supplies the power supply from thepower source to the battery of the battery module and a chargecontroller that controls a power supply from the charger to the batteryof the battery module, the charge control unit is configured by theplurality of charge controllers respectively provided to the batterymodules, and in each of the battery modules, the charge controllerprovided to the battery module is configured to perform the followingoperations: (6-1) determine whether there is an indication that thebattery modules to which the charge controller is not provided areundergoing charging, and (6-2) upon determining that there is anindication that the battery modules to which the charge controller isnot provided are undergoing charging in operation (6-1), stop the powersupply from the charger provided to the battery module to which thecharge controller is provided to the battery of the battery module. 7.The storage system according to claim 6, wherein each of the chargecontrollers is configured to perform the following operations: (7-1)determine upon completing operation (6-2), whether there is anindication that the battery modules to which the charge controller isnot provided are undergoing charging, and (7-2) upon determining thatthere is an indication that the battery modules to which the chargecontroller is not provided are not undergoing charging in operation(7-1), initiate the power supply from the charger provided to thebattery module to which the charge controller is provided to the batteryof the battery module.
 8. The storage system according to claim 7,wherein each of the charge controllers is configured to perform thefollowing operations: (8-1) determine, upon determining that there is anindication that the battery modules to which the charge controller isnot provided are undergoing charging in operation (7-1), whether thebattery module to which the charge controller is provided is satisfyingspecific requirements, (8-2) upon determining that the battery module towhich the charge controller is provided is satisfying the specificrequirements in operation (8-1), initiate the power supply from thecharger provided to the battery module to which the charge controller isprovided to the battery of the battery module, and (8-3) upondetermining that the battery module to which the charge controller isprovided is not satisfying the specific requirements in operation (8-1),stop the charger provided to the battery module to which the chargecontroller is provided to charge the battery of the battery module. 9.The storage system according to claim 6, wherein the plurality ofbattery modules are configured in one or more battery module pairs, ineach of the battery module pairs, the battery modules are connected by afirst signal line and a second signal line, over the first signal line,a signal indicating a charge state in one of the battery modules flowsfrom the one of the battery modules to the other battery module in thebattery module pair, over the second signal line, a signal indicating acharge state in the other battery module flows from the other batterymodule to the one battery module in the battery module pair, and thecharge controller provided to the one battery module determines whetherthe other battery module is undergoing charging by referring to thesignal flowing over the second signal line.
 10. The storage systemaccording to claim 1, wherein upon a detection being made that apredetermined number of the plurality of controller components are in astate of second power consumption that is lower in power consumptionthan a state of first power consumption, a quantity of the batterymodules equal to the predetermined number of the battery Modules arecharged concurrently.
 11. The storage system according to claim 7,wherein the plurality of battery modules are configured in one or morebattery module pairs, in each of the battery module pairs, the batterymodules are connected by a first signal line and a second signal line,over the first signal line, a signal indicating a charge state in one ofthe battery modules flows from the one of the battery modules to theother battery module in the battery module pair, over the second signalline, a signal indicating a charge state in the other battery moduleflows from the other battery module to the one battery module in thebattery module pair, and the charge controller provided to the onebattery module determines whether the other battery module is undergoingcharging by referring to the signal flowing over the second signal line.12. The storage system according to claim 8, wherein the plurality ofbattery modules are configured in one or more battery module pairs, ineach of the battery module pairs, the battery modules are connected by afirst signal line and a second signal line, over the first signal line,a signal indicating a charge state in one of the battery modules flowsfrom the one of the battery modules to the other battery module in thebattery module pair, over the second signal line, a signal indicating acharge state in the other battery module flows from the other batterymodule to the one battery module in the battery module pair, and thecharge controller provided to the one battery module determines whetherthe other battery module is undergoing charging by referring to thesignal flowing over the second signal line.
 13. The storage systemaccording to claim 6, wherein upon a detection being made that apredetermined number of the plurality of controller components are in astate of second power consumption that is lower in power consumptionthan a state of first power consumption, a quantity of the batterymodules equal to the predetermined number of the battery modules arecharged concurrently.
 14. The storage system according to claim 7,wherein upon a detection being made that a predetermined number of theplurality of controller components are in a state of second powerconsumption that is lower in power consumption than a state of firstpower consumption, a quantity of the battery modules equal to thepredetermined number of the battery modules are Charged concurrently.15. The storage system according to claim 8, wherein upon a detectionbeing made that a predetermined number of the plurality of controllercomponents are in a state of second power consumption that is lower inpower consumption than a state of first power consumption, a quantity ofthe battery modules equal to the predetermined number of the batterymodules are charged concurrently.
 16. The storage system according toclaim 9, wherein upon a detection being made that a predetermined numberof the plurality of controller components are in a state of second powerconsumption that is lower in power consumption than a state of firstpower consumption, a quantity of the battery modules equal to thepredetermined number Of the battery modules are charged concurrently.